O my, you all want me to show off my ignorance now, right? Serves me right, I did put bold statements in the post.

Well, here goes. This is my simpleminded interpretation, a working theory for my daily life.
First off: a faulty SNP doesn't mean the whole enzyme it codes for is faulty (I think. I'm not even sure anymore)
More often then not there are other enzymes dabbling in the same function. So: don't panic, it's usually not a white/black situation.
I'm mainly interested in the enzymes and their functions. There's a lot we don't know yet. A lot.
I'm working with these two diagrams to broadly understand how the cycles work in my cells. They both represent the same processes and they concern both the energy supply of cells as well as getting rid of toxins and stuff the cell doesn't need anymore. Once I studied them intensely and understood them. Now I've forgotten. Sources are
Yasko,
Heartfixer and
AutismNTI.
The top one shows the five "separate" cycles that feed of one another.
The lower one shows basically the same but shows which metals frustrate which step. For example at the orange enzyme called DHPR there's a grey "stopper" called Alum.
Don't bother understanding these diagrams if you've never seen them before, just look at them a bit, notice enzymes and products and then move on.
Now I combine my SNPs into this. I only look at the homozygous mutations because heterozygous mutations won't hinder enzyme production too much, I figure. Even homozygous mutations do not mean the resulting enzyme is a total failure. It may just function considerably less.
+/+ MTR A2756G, MTRR A669 are a nice set, frustrating the usual path between the Folate Cycle and the Methylation Cycle (4th and 5th cycle) in a double way. MTR is the enzyme that gathers B12 (and vitD) but it's not working too well. MTRR is a brake that's applied to it because otherwise MTR syphones away all the B12.
My brake is broken, it allows MTR to grab all the B12 it can get hold of and lets it throws it in the bin. Wrapping it in vit D in the proces.
So here I am, having all the symptoms of B12 shortage and vit D shortage even though blood levels look good. MTR/MTRR explains why: I'm expelling B12 and vit D at cell level. And Folate is hardly usable.
But I've read cells find another way to convert folate into the 5th cycle. It's called "the long route". Nevertheless, it tells me my cells cannot properly use the folate in my cells, blood or food. So don't bother eating it. (Metafolin, on the other hand, works like a charm. But I'll get to bypassing enzymes later on.)
So. Leaking vit D huh?
But the enzymes for my Vit D receptors are not whole. My VDR Tag is out and VDR Fok is unknown. There's a high probability my vit D receptors are not too good at their functioning and on top of that vit D gets used up fast through this alternative path way. This coincides with a ridiculous sensitivity to vit D shortage, it will mess up my brain chemistry.
This brings me to the neurotransmitter part of these cycles. They are at the bottom. Dopamine, Serotonine, the lot.
I have a natural tendency to be "quicksilvery." Quick, smart, easily excitable, force full, pushing, confident, intense, concentrated, dominant, multi tasking, survivor in complex situations. Also sunny disposition.
These are all the hallmarks of lots of serotin and dopamine. This coincides with a faulty dismembering enzyme that breaks down these excitatory neurotransmitters. This enzyme is MAO A and I am homoz. for one of its building instructions: MAO A R297R.
(People with ADHD have a MAO A enzyme that works too hard: their happy and concentrating neurotransmitters are broken down too fast, while the person still had use for it.)
I'm not really sure but because the 4th and the 5th cycle are hampered in my case (and some heteroz. snp's are involved in the 3rd and 4th also) I figured excess stuffs that would usually go through the cycles are now more easily thrown away (downwards in the diagrams). Resulting in excess dopamine and serotonin.
Next: I had my hair analyzed and found I had the normal amount of heavy metals. Which is too much. And my blood Zinc was way too low. Looking at the second diagram I saw which metals frustrated which enzyme. I don't understand it fully but I now know Lead and Aluminium are BIG THINGS when cell processes are concerned. Any amount is too much.
With my processes being very vulnerable by the time I got really ill I understood why any vaccin (with Alum carrier) or any lead exposure would wipe me out.
I now also understood why for the first 18 months of my illness I had severe brainfog. (as in: I didn't know my name on most days and didn't care). This was not only due to the metals but when these basic processes fail, you cannot expect your brain to still function. I was also malnourished, at cell level, because there's a full spectrum of amino acids and minerals needed for everything to work optimal.
Once you reach a level of malfunction where everything goes, well, everything goes. There's no robustness left. No reserve. No magic pill either.
When I learned about these cell cycles I drew this conclusion: "not only is my energy supply at cell level hindered, also the means to convert homocysteine into harmless stuffs is hindered. I think my cells are filled to the brim with the toxins they cannot process properly, especially ammonia. And they are lacking full spectrum amino acids and minerals."
This is the strategy I thought up:
- don't put any more stress on the cell. No "ammonia-rich-foods".
- start supplying the full things: full spectrum mineral supplements and full protein (i.e. egg yoke, gelatine or chicken broth)
- the system is totally overwhelmed at the moment. Any little thing is too much now. So stay away from all heavy metals. Get Amalgam fillings out. Stop breathing exhaust fumes. Don't ever pick up stained glass as a hobby again. Stop using aluminium containers and pots and pans (use glass and ceramics instead).
- take the time to get rid of the waste the cells have gathered over the years. Work slow.
- allow time for new cells to be build. Don't expect results overnight.
- preserve energy. Rest. And aid body in waste removal: gently stretch and yawn while you're in your bed all day.
- (later on there was the reduction of strain on the nervous systems, what with me possessing easily excited neurotransmitters and stress being a very physical altering modus)(also I educated myself on hormones. Especially vit D, progesteron, cortisol and insuline. You don't want insuline raging through your body, it's a poison)
Think I'm at the end of my post, I think.
I learned to match food I ate to changes is moods. To me, brain chemistry and digestion are much a part of these cell cycles I show here. It has all to do with metals, hormones, neurotransmitters, proteins, any sort of "-ine" floating through the body. Most of them synthesized and broken down by enzymes in cells.
By now, a few years after I came back from the brain fog dead, I think most of my cells are no longer overwhelmed. No longer filled to the brim with ammonia. I've slowly started to aid the methylation cycle with both mB12 and Metafolin. Oei!

Gotta take it slow. These cycles are jumping at the chance to open up the throttle. I need to have in place: all co-factors, all ways of waste disposal.
Well. This post has taken two hours to write. I forgot if there's anything else I want to say. I'm going to post it and see how it looks. Perhaps edit it a bit. I still haven't learned how to properly insert/upload a .pdf
I'm sure I didn't answer all the questions so feel free to remind me.